Unix Timestamp Converter

Convert Unix timestamps to dates and back

Unix time (epoch time) counts seconds — or in JavaScript's case, milliseconds — since January 1, 1970 UTC. It's the standard way computers store and exchange timestamps, because it's unambiguous, timezone-independent, and trivial to compare or sort. This tool converts a timestamp to a human-readable date in your local timezone or UTC, and converts a date back into a timestamp.

Common pitfalls this tool helps avoid

• Seconds vs. milliseconds: Unix APIs and databases (like PostgreSQL, most REST APIs) typically use seconds; JavaScript's Date.now() and many logging systems use milliseconds. Mixing them up produces a date wildly in the past (1970) or far in the future. Use the unit selector to match your source.
• Timezone confusion: A timestamp itself has no timezone — it's the same instant everywhere. The date/time you see depends on which timezone you display it in. Toggle "Treat as UTC" to control whether your typed date/time is interpreted in UTC or your browser's local timezone.
• Off-by-one date bugs: These often come from exactly this seconds/milliseconds or timezone mismatch — double-check both before assuming your code has a logic bug.

Typical use cases

• Debugging logs: Convert a raw epoch timestamp from a log line into a readable date.
• API testing: Generate a timestamp for a request payload, or verify an exp/iat value from a JWT (see the JWT Decoder).
• Scheduling & reporting: Product managers converting a "campaign start" date into the epoch value an engineering ticket or config expects.

For the full story on why computers track time this way, see Unix Timestamps Explained: Why Computers Count Time in Seconds.

Frequently Asked Questions